使用 StreamTokenizer () 、 HashMap() 、 HashSet() 计算词频。在 Java 核心

Question

import java.io.*;
import java.util.*;
class A {
    public static void main(String args[]) throws Exception {
        Console con = System.console();
        String str;
        int i=0;
  
        HashMap map = new HashMap();
        HashSet set = new HashSet();
 
        System.out.println("Enter File Name : ");
        str = con.readLine();
        File f = new File(str);
        f.createNewFile();
        
        FileInputStream fis = new FileInputStream(str);
        StreamTokenizer st = new StreamTokenizer(fis);
        while(st.nextToken()!=StreamTokenizer.TT_EOF) {
         String s;
    
         switch(st.ttype) {
             case StreamTokenizer.TT_NUMBER:  s = st.nval+"";
             break;
              case StreamTokenizer.TT_WORD:    s = st.sval;
               break;
                default: s = ""+((char)st.ttype);
            }


            map.put(i+"",s);
            set.add(s);
            i++;
        }
 
        Iterator iter = set.iterator();
        System.out.println("Frequency Of Words :");
        while(iter.hasNext()) {
          String word;
          int count=0;
          word=(String)iter.next();
          
            for(int j=0; j<i ; j++) {
             String word2;
              word2=(String)map.get(j+"");
               if(word.equals(word2))
                count++;
            }
            System.out.println(" WORD : "+ word+" = "+count);
        }
        System.out.println("Total Words In Files: "+i);
    }
}

In This code First I have already created a text file which contains the following data :

@Hello Hii World# * c++ java salesforce

And the output of this code is :

**词频：

字数：# = 1

字数：@=1

WORD : c = 1

WORD : 销售人员 = 1

字数：* = 1

WORD : Hii = 1

字数：+=2

字数：java = 1

WORD : 世界 = 1

WORD : 你好 = 1

文件中的总字数：11**

where i am unable to find why this shows c++ as a seperate words . I want to combine c++ as a single word as in the output

Answer 1

你可以这样做

    // Create the file at path specified in the String str
    // ...
    HashMap<String, Integer> map = new HashMap<>();
    InputStream fis = new FileInputStream(str);
    Reader bufferedReader = new BufferedReader(new InputStreamReader(fis));

    StreamTokenizer st = new StreamTokenizer(bufferedReader);
    st.wordChars('+', '+');
    while(st.nextToken() != StreamTokenizer.TT_EOF) {
        String s;

        switch(st.ttype) {
            case StreamTokenizer.TT_NUMBER:
                s = String.valueOf(st.nval);
                break;
            case StreamTokenizer.TT_WORD:
                s = st.sval;
                break;
            default:
                s = String.valueOf((char)st.ttype);
        }
        Integer val = map.get(s);
        if(val == null)
            val = 1;
        else
            val++;
        map.put(s, val);
    }

    Set<String> keySet = map.keySet();
    Iterator<String> iter = keySet.iterator();
    System.out.println("Frequency Of Words :");
    int sum = 0;
    while(iter.hasNext()) {
        String word = iter.next();
        int count = map.get(word);
        sum += count;
        System.out.println(" WORD : " + word + " = " + count);
    }
    System.out.println("Total Words In Files: " + sum);

请注意，我已经使用泛型而不是 HashMap 和 Iterator 的原始版本更新了您的代码。此外，您用于 StreamTokenizer 的构造函数已被弃用。同时使用 map 和 set 是没有用的，因为您可以使用 .keySet() 方法迭代 map 的键集。映射现在从字符串（单词）到整数（单词数）。

无论如何，对于你做的这个例子，我认为一个简单的拆分方法会更合适。

有关 StreamTokenizer 的 wordChars 方法的更多信息，您可以查看 #wordChars(int, int)

使用 StreamTokenizer () 、 HashMap() 、 HashSet() 计算词频。在 Java 核心

Calculating Word Frequency Using StreamTokenizer () , HashMap() , HashSet(). in Java Core

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